ENVIRONMENTAL ASSESSMENT FOR AMENDMENT OF PROJECT LICENSE TO REPLACE BOAT FUEL DOCK AND ASSOCIATED INFRASTRUCTURE AT DIABLO LAKE Skagit River Hydroelectric Project ---- FERC Project No. 553-238 Washington Federal Energy Regulatory Commission Office of Energy Projects Division of Hydropower Administration and Compliance 888 First Street, NE Washington, D.C. 20426 May 2021 TABLE OF CONTENTS LIST OF FIGURES AND TABLES ............................................................................... iv ACRONYMS AND ABBREVIATIONS ......................................................................... v I. INTRODUCTION ................................................................................................... 1 II. PURPOSE AND NEED OF ACTION ................................................................... 1 III. PROPOSED ACTION AND ALTERNATIVES .................................................. 2 A. Project Description ................................................................................................. 2 B. Description of the Proposed Action ....................................................................... 3 C. Proposed Environmental Measures ........................................................................ 5 D. No-Action ............................................................................................................... 8 IV. CONSULTATION AND COMPLIANCE ............................................................ 9 A. Pre-filing Consultation ........................................................................................... 9 B. Public Notice ........................................................................................................ 10 C. Threatened and Endangered Species ................................................................... 10 D. Coastal Zone Management Act ............................................................................ 12 E. National Historic Preservation Act ...................................................................... 13 F. Wild and Scenic Rivers Act ................................................................................. 14 V. AFFECTED ENVIRONMENT AND ENVIRONMENTAL EFFECTS .............. 15 A. General Description of the River Basin ............................................................... 15 B. Geographic and Temporal Scope of Effects Analysis ......................................... 15 C. Proposed Action ................................................................................................... 17 1. Water Quantity ...................................................................................................... 17 2. Water Quality ....................................................................................................... 18 3. Aquatic Resources ................................................................................................ 21 4. Terrestrial Resources ............................................................................................ 23 5 Threatened and Endangered Species ..................................................................... 25 6. Recreation and Aesthetics .................................................................................... 29 7. Cultural Resources ................................................................................................ 31 VI. CONCLUSION ...................................................................................................... 32 A. Staff Recommended Measures ............................................................................ 32 ii B. Unavoidable Adverse Effects .............................................................................. 33 VII. FINDING OF NO SIGNIFICANT IMPACT ..................................................... 34 VIII. LITERATURE CITED ......................................................................................... 34 IX. LIST OF PREPARERS ........................................................................................ 35 iii LIST OF FIGURES AND TABLES Figure 1: Project Vicinity Map ................................................................................... 7 Figure 2: Proposed Fuel Dock Location ..................................................................... 8 Figure 3: Geographic Scope of Analysis ................................................................... 16 Figure 4: Area of Auditory and Visual Effects Aanalysis ...................................... 16 Table 1: Designated uses of waters in the project area/WRIA 4 ............................ 18 Table 2: Water quality criteria for water resources in the project area ................ 19 Table 3. Federally listed wildlife species which may use habitat located in or near the project area ............................................................................................................ 25 iv ACRONYMS AND ABBREVIATIONS 1995 Order Order Accepting Settlement Agreement, Issuing New License, and Terminating Proceeding 2018 BO 2018 Biological Opinion Advisory Council Advisory Council on Historic Preservation BMPs best management practices Commission or FERC Federal Energy Regulatory Commission Corps U.S. Army Corps of Engineers CY cubic yards CZMA Coastal Zone Management Act CZMP Coastal Zone Management Program dB decibels EA Environmental Assessment ESA Endangered Species Act Forest Service U.S. Forest Service FWS U.S. Fish and Wildlife Service NAVD 88 North American Vertical Datum of 1988 NEPA National Environmental Policy Act NHPA National Historic Preservation Act National Register National Register of Historic Places PA Programmatic Agreement Park Service U.S. National Park Service PM&Es protection, mitigation, and enhancement measures Seattle or Licensee City of Seattle SEPA Washington State Environmental Policy Act Washington DOE Washington Department of Ecology Washington DFW Washington Department of Fish and Wildlife Washington DHAP Washington Department of Archaeological and Historic Preservation WRIA-4 Washington Watershed Resource Inventory Area 4 v I. INTRODUCTION A. Application Type: Non-Capacity Amendment of Project License B. Date Filed: June 11, 2020 C. Applicant’s Name: City of Seattle, Washington (Seattle) D. Waterbody: Skagit River E. County and State: Snohomish, Skagit, and Whatcom counties, Washington F. Federal Lands: The project occupies a portion of the Ross Lake National Recreation Area administered by the U.S. National Park Service (Park Service) and the Mount Baker National Forest administered by the U.S. Forest Service (Forest Service). II. PURPOSE AND NEED OF ACTION On June 11, 2020, Seattle filed an application for a non-capacity amendment to construct a replacement fuel dock at Diablo Lake, including the marine fueling dispenser and bulkhead. According to Seattle, the fuel dock is essential to servicing marine vessels that support routine operation and maintenance of Ross and Diablo Dams, Ross and Diablo Reservoirs, and Ross Powerhouse. There is no roadway access to Ross Dam and Ross Powerhouse, so all personnel, equipment, and materials must be transported via marine vessel across Diablo Lake. The fuel dock is also necessary to meet Seattle’s obligations set forth in the Commission-approved Recreation Plan under Article 412 of the project license1 to provide boat tours of Diablo Lake and ferry services facilitating access for visitors between Diablo Lake and Ross Lake. As such, marine vessels are necessary for Seattle to meet its many obligations under the project license. The new fuel dock assembly will provide safer access to marine fueling facilities, reduce the risk of fuel spills, and facilitate access for all vessels to the fuel dock at low lake levels. This environmental assessment (EA) is being prepared to satisfy the Commission’s responsibilities under the National Environmental Policy Act (NEPA).2 In 1 Order Approving an Interim Recreational Resources Plan (77 FERC ¶ 62,096) issued November 19, 1996. 2 On July 16, 2020, the Council on Environmental Quality issued a final rule, Update to the Regulations Implementing the Procedural Provisions of the National 1 this EA, Commission staff examine the environmental effects associated with replacing the fuel dock and marine fueling dispenser, as well as repairing the bulkhead. A no- action alternative to the proposed project will also be examined along with any recommended staff conditions which may become a part of any license amendment that may be issued. III. PROPOSED ACTION AND ALTERNATIVES A. Project Description On May 16, 1995, the Commission issued a new license to Seattle for the Skagit River Project that authorized the continued operation of a project consisting of three developments: (1) the Ross Development; (2) the Diablo Development; and (3) the Gorge Development.3 All three developments are surrounded by the Ross Lake National Recreation Area which is managed by the Park Service. As amended,4 the project is as described below. Ross Development The Ross facilities consist of: (1) a concrete arch dam rising 540 feet from bedrock to crest, with a 240-foot-wide spillway and 12 radial gates; (2) a 11,680-acre reservoir with a total storage capacity of 1,435,000 acre-feet; (3) an intake structure; (4) two 26-foot-diameter power tunnels, 1,800 feet long and 1,634 feet long; (5) four 16- foot-diameter penstocks, 350 feet long; (6) a power plant with four generating units having a combined authorized installed capacity of 352.5 megawatts (MW); (7) transmission lines extending